FDA OKs Patch to Treat Depression
Using Emsam in Lower Doses May Avoid Concerns About Drug Interactions
Feb. 28, 2006 -- The FDA has approved the first skin patch for use in treating major depression.
The once-a-day patch, called Emsam, works by delivering selegiline, a monoamine oxidase inhibitor or MAOI, through the skin and into the bloodstream.
Selegiline isn't a new drug. It was initially approved in capsule form for use in Parkinson's disease.
Like other MAOIs, selegiline has carried warnings about possible dangerous interactions with certain foods and drinks, including aged cheeses and tap beer. The new patch's lowest dose may avoid some of those interactions.
"At its lowest strength, Emsam can be used without the dietary restrictions that are needed for all oral MAO inhibitors that are approved for treating major depression," states an FDA news release.
However, higher doses of the patch require dietary restrictions, and all of the doses carry other cautions.
The FDA's Steven Galson, MD, MPH, commented on the new patch, in a news release.
"Emsam provides a significant advance because at least in its lowest dose patients can use the drug without the usual dietary restrictions associated with these types of drugs known as MAO inhibitors," says Galson, who directs the FDA's Center for Drug Evaluation and Research.
Major depression is common in the U.S. Depression can often be treated by methods including counseling and antidepressants, which come in several forms including MAOIs. Depression symptoms can include sadness, fatigue, insomnia, changes in weight or appetite, loss of interest in usual activities, restlessness, suicide attempts, and suicidal thinking.
How MAOIs Work
MAOIs usually require specific dietary restrictions because when combined with certain foods they can cause a sudden, large increase in blood pressure. That problem, called "hypertensive crisis," can lead to a stroke and death.
Here's how hypertensive crisis can happen.
MAOIs block an enzyme called monoamine oxidase (MAO). Blocking MAO in the brain is thought to have antidepressant effects by preventing the breakdown of certain brain chemicals. But the body also uses MAO to break down a protein called tyramine, which we get from consuming aged cheeses, tap beer, and other foods and drinks.
If tyramine isn't broken down, the body may absorb too much of it. The result can be a hypertensive crisis -- in other words, a dangerous spike in blood pressure.
Symptoms of Hypertensive Crisis
Symptoms of a hypertensive crisis include sudden onset of severe headache, nausea, blurry vision, a fast heartbeat or a change in the way your heart beats (palpitations), sweating, and confusion.
"Patients who have these symptoms should get medical care right away," states the FDA.
The lowest dose of the MAOI patch, which delivers 6 milligrams of the medication over a 24-hour period, can be used without such dietary restrictions.
About the New Patch
The Emsam patch will be made available in three sizes that deliver 6 milligrams, 9 milligram, or 12 milligrams of selegiline per 24 hours. The patch sandwiches the drug between two lining layers.